21213160 has 16 divisors (see below), whose sum is σ = 47729700. Its totient is φ = 8485248.

The previous prime is 21213149. The next prime is 21213163. The reversal of 21213160 is 6131212.

It can be written as a sum of positive squares in 2 ways, for example, as 18164644 + 3048516 = 4262^2 + 1746^2 .

It is not an unprimeable number, because it can be changed into a prime (21213163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265125 + ... + 265204.

Almost surely, 2^21213160 is an apocalyptic number.

21213160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213160 is an abundant number, since it is smaller than the sum of its proper divisors (26516540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213160 is a wasteful number, since it uses less digits than its factorization.

21213160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530340 (or 530336 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21213160 is about 4605.7746362583. The cubic root of 21213160 is about 276.8227567132.

Adding to 21213160 its reverse (6131212), we get a palindrome (27344372).

The spelling of 21213160 in words is "twenty-one million, two hundred thirteen thousand, one hundred sixty".